...and this is how i know:
after a night of excessive drinking " lots o' fun, i woke up after sleeping 6 hours " decided to go for a run. not just a fun run, but a run with purpose - i had to go get my car from the bar parking lot. mapquest said it was 4.67 miles away, so i figured i could do it.
a good run right away does fight a hangover quite well, though. i'm finally starting to feel it and it's 1:00.